Lactose is the major sugar present in milk.
Due to lactose intolerance and limited use its hydrolysis into its constituent sugars, glucose and galactose, is often desirable, resulting in:
Acid hydrolysis of lactose is possible, but colour and bitterness are produced. Also the process has shown to be relatively inflexible (only desmineralized, deproteinized streams can be processed). Commercialisation of this process has not therefore taken place.
Enzymatic hydrolysis with b-galactosidase (lactases) presents a good alternative.
As the enzyme is inhibited by galactose (one of the reaction products) is very dificult to achieve complete hydrolysis unless high concentrations of enzyme are used.
Lactases can be immobilized on a variety of supports for industrial use.
Lactose hydrolysis are applied in liquid milk, milk powders, fermented milk products, concentrated milk products (e.g. ice cream), whey for animal feed, whey, deproteinized whey (after ultrafiltration).